DESCRIPTION: (Applicant's Description) The purpose of this study is to investigate the relationship between human papillomaviruses (HPV) and adeno-associated virus (AAV) in the development of cervical squamous intraepithelial lesions (SIL) among low-income South Carolinians. Through an R29, the investigators are currently conducting a nested case-control study of HPV, diet, smoking, race, and cervical neoplasia risk. They propose, for this R03, to additionally analyze cervical samples, initially collected for HPV typing, for the presence of adeno-associated virus (AAV). This tumor-suppressor, helper-dependent virus has been shown to be sexually transmitted and may interact with the oncogenic HPV DNA types to affect cervical neoplasia risk. They hypothesize that women who develop SIL will be more likely to have one of the oncogenic HPV DNA types and no AAV infection compared with who whose cervices remain normal throughout follow-up. For the on-going R29, the investigators have identified (1991-1992) and followed a cohort of 6,523 women (9,293 cervical samples) attending family planning clinics provided by the state health department in South Carolina. Over this follow-up (through 1996), they have identified 249 women who developed SIL (cases) and 330 controls from a pool of 2,652 with Pap smears remaining normal over follow-up. They are currently conducting HPV analyses using the MY09/MY11 system for 1,013 cervical samples from these cases and controls (44% of women have time-series samples). Telephone interviews are also being conducted now with cases and controls to determine subjects' cigarette smoke exposure, age, education, parity, contraceptive use, sexual and reproductive history, and history of sexually transmitted diseases. Diet was assessed using the Block self-administered food frequency questionnaire. The analyses will compare cases with controls regarding HPV and AAV infection status and will control for smoking, diet, race, and sexual risk factors for SIL.